1. Field of the Invention
The present invention relates to a substrate processing apparatus that performs a process on a substrate.
2. Description of Related Art
Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, and photomasks, and other substrates to various types of processing. For example, a process is performed on a substrate using various types of chemical liquids in the substrate processing apparatus (see JP 2008-251890 A, for example).
In a resist coating processing section in which a resist is applied to the substrate as the chemical liquid, the resist stored in a chemical liquid bottle is normally led to a trap tank by a discharge pump. The resist stored in the trap tank is led to a discharge nozzle by the discharge pump. The resist is purified by a filter on the route from the trap tank to the discharge nozzle. If a discharge valve is open, the resist is discharged from the discharge nozzle, and if the discharge valve is closed, the discharge of the resist from the discharge nozzle is stopped.